1. Field of the Invention
The present invention relates to a steerable guidewire and more particularly to a steerable guidewire having a swivel tip which may be precisely deflected. The guidewire is particularly suitable for use in conjunction with placement of a spinal cord stimulation lead in the epidural space of a patient, or alternatively, for the insertion of an endovascular product into a blood vessel of the patient.
2. Description of the Prior Art
The use of guidewires is well established to place catheters and other devices in target regions of the body. Generally, the guidewire is inserted into a vessel, and is navigated to a desired location. The catheter is fed over the guidewire and advanced through the vessel until the distal end of the catheter is positioned at a desired location. The guidewire is then retracted from the catheter and the catheter is left in the vessel to perform the endovascular intervention.
A guidewire may have a stiffness and flexibility along its length such that rotation or torque applied to the proximal section (e.g., to the hub) results in navigating the distal tip. Under fluoroscopy, a skilled practitioner can advance and torque the guidewire while observing its trajectory and location until a desired target region is reached. While this technique is generally acceptable, situations arise when even a skilled physician is not able to deflect the tip of the guidewire a sufficient degree to reach the target destination.
Various steerable guidewires have been described to provide controlled deflection and steering. Examples of steerable guidewires and devices are described in U.S. Pat. No. 7,481,778 to Cedro et al.; U.S. Pat. No. 7,449,002 to Wenstad; U.S. Pat. Nos. 4,815,478 and 4,813,434 both to Maurice Buchbinder et al.; U.S. Pat. No. 5,037,391 to Julius G. Hammerslag et al.; U.S. Pat. No. 5,203,772 to Gary R. Hammerslag et al.; U.S. Pat. No. 6,146,338 to Kenneth C. Gardeski et al.; U.S. Pat. No. 6,126,649 to Robert A. VanTassel et al.; U.S. Pat. No. 6,059,739 to James C. Baumann; U.S. Pat. Nos. 5,372,587 and 4,998,916 both to Julius G. Hammerslag et al.; U.S. Pat. No. 4,940,062 to Hilary J. Hampton et al.; U.S. Pat. No. 8,298,161 to Vargas; and U.S. Pat. No. 7,682,319 to Martin et al.
However, despite the above mentioned patents, there is still a need for a guidewire having more precise control and steering. There is still a need for a guidewire having a more complete range of motion, and that is reliable in each direction.